====== Guo-Fu Tseng: Implement and Port Ethernet Drivers for gPXE ======

===== Notes: TCP Window Size and RX Csum Offload Benchmark =====

I've done some benchmark with imgfetch a 500MByte image via HTTP.
The test was done by directly connect two computer with a CAT.6 cable:
  * Server:
    * Processor: Intel(r) Core(tm)2 Quad CPU    Q8400  @ 2.66GHz
    * RAM: 8G DDRII-800
    * MB Chip: G965 (ICH8)
    * NIC: Marvell 88E8056 PCI-E Gigabit Ethernet Controller
    * OS: Gentoo (Linux 2.6.33.3)
    * HTTP Server: Lighttpd 1.4.26
  * Client:
    * Processor: AMD Athlon(tm) 64 Processor 3000+ (1.8HGz)
    * RAM: 2G DDR400
    * MB Chip: nVidia CK804
    * NIC: JMicron JMC250 PCI Express Gigabit Ethernet Controller
    * OS: gPXE latest    

[[http://git.etherboot.org/?p=people/cooldavid/gpxe.git;a=shortlog;h=refs/heads/jme_driver_cso|The RX checksum offload source tree]]

The following table shows the result of different TCP_MAX_WINDOW_SIZE
and with or without RX checksum offloading.

^             HTTP imgfetch benchmark          ^^^
^ WinSize ^ Without RX Offload ^ With RX Offload ^
|           Window Size 1024 byte step         |||
^    4096 |      136Mbit/s     |     136Mbit/s   |
^    5120 |      200Mbit/s     |     208Mbit/s   |
^    6114 |      224Mbit/s     |     264Mbit/s   |
^    7168 |      264Mbit/s     |     288Mbit/s   |
^    8192 |      256Mbit/s     |     272Mbit/s   |
^    9216 |      368Mbit/s     |     416Mbit/s   |
^   10240 |      368Mbit/s     |     400Mbit/s   |
^   11264 |      424Mbit/s     |     496Mbit/s   |
^   12288 |      448Mbit/s     |     536Mbit/s   |
^   13312 |      496Mbit/s     |     616Mbit/s   |
^   14436 |      496Mbit/s     |     592Mbit/s   |
^   15360 |      528Mbit/s     |     704Mbit/s   |
|           Window Size 2048 byte step         |||
^   16384 |      528Mbit/s     |     696Mbit/s   |
^   18432 |                    |     768Mbit/s   |
^   20480 |                    |     824Mbit/s   |
^   22528 |                    |     880Mbit/s   |
^   24576 |                    |     896Mbit/s   |
|                    Full Speed                |||
^   32768 |      536Mbit/s     |     896Mbit/s   |
^   65532 |      536Mbit/s     |     896Mbit/s   |